1. Field of the Invention
This invention relates generally to a semiconductor fabrication process, and, more particularly, to controlling the semiconductor fabrication process based on tool health data provided by a fault detection and classification unit.
2. Description of the Related Art
There is a constant drive within the semiconductor industry to increase the quality, reliability and throughput of integrated circuit devices, e.g., microprocessors, memory devices, and the like. This drive is fueled by consumer demands for higher quality computers and electronic devices that operate more reliably. These demands have resulted in a continual improvement in the manufacture of semiconductor devices, e.g., transistors, as well as in the manufacture of integrated circuit devices incorporating such transistors. Additionally, reducing the defects in the manufacture of the components of a typical transistor also lowers the overall cost per transistor as well as the cost of integrated circuit devices incorporating such transistors.
Generally, a set of processing steps is performed on a group of wafers, sometimes referred to as a xe2x80x9clot,xe2x80x9d using a variety of processing tools, including photolithography steppers, etch tools, deposition tools, polishing tools, rapid thermal processing tools, implantation tools, etc. The technologies underlying semiconductor processing tools have attracted increased attention over the last several years, resulting in substantial improvements.
One technique for improving the operation of a semiconductor processing line includes using a factory wide control system to automatically control the operation of the various processing tools. The manufacturing tools communicate with a manufacturing framework or a network of processing modules. Each manufacturing tool is generally connected to an equipment interface. The equipment interface is connected to a machine interface which facilitates communications between the manufacturing tool and the manufacturing framework. The machine interface can generally be part of an Advanced Process Control (APC) system. The APC system initiates a control script based upon a manufacturing model, which can be a software program that automatically retrieves the data needed to execute a manufacturing process. Often, semiconductor devices are staged through multiple manufacturing tools for multiple processes, generating data relating to the quality of the processed semiconductor devices.
During the fabrication process, various events may take place that affect the performance of the devices being fabricated. That is, variations in the fabrication process steps result in device performance variations. Factors, such as feature critical dimensions, doping levels, particle contamination, film optical properties, film thickness, film uniformity, etc., all may potentially affect the end performance of the device. Various tools in the processing line are controlled in accordance with performance models to reduce processing variation. Commonly controlled tools include photolithography steppers, polishing tools, etching tools, and deposition tools. Pre-processing and/or post-processing metrology data is supplied to process controllers for the tools. Operating recipe parameters, such as processing time, are calculated by the process controllers based on the performance model and the metrology data to attempt to achieve post-processing results as close to a target value as possible. Reducing variation in this manner leads to increased throughput, reduced cost, higher device performance, etc., all of which equate to increased profitability.
As noted, metrology data is one way of controlling process variations. While reliance on the metrology data for process control is generally effective, such data typically only provides information associated with measurements of the processed wafers, information such as critical dimensions and doping levels. Thus, the ability to control process variations may be somewhat limited if the process control is based primarily on the underlying metrology data that is provided to the controller.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
In one embodiment of the present invention, a method is provided for a process control based on tool health data. The method comprises processing a workpiece using a processing tool, receiving trace data associated with the processing of the workpiece from the processing tool and determining at least one value associated with a health of a portion of the processing tool based on at least a portion of the received trace data. The method further comprises adjusting processing of another workpiece based on the determined health value.
In another embodiment of the present invention, an apparatus is provided for a process control based on tool health data. The apparatus comprises an interface and a controller that is communicatively coupled to the interface. The interface is adapted to receive trace data associated with processing a semiconductor wafer of a lot. The controller is adapted to determine health data associated with one or more components of the processing tool based on at least a portion of the received trace data and adjust processing of another semiconductor wafer in the lot based on the determined health data.
In a further embodiment of the present invention, an article comprising one or more machine-readable storage media containing instructions is provided for process control based on tool health data. The one or more instructions, when executed, enable the processor to receive trace data associated with processing of a wafer by a processing tool, generate one or more health statistics associated with the operation of the processing tool based on at least a portion of the received trace data and provide at least one of the health statistic to a controller to adjust one or more parameters of the recipe based on the at least one health statistic.
In a further embodiment of the present invention, a system is provided for process control based on tool health data. The system comprises a processing tool, a fault detection and classification system and a controller. The processing tool is adapted to provide trace data associated with the processing of a wafer of a lot. The fault detection and classification system is adapted to determine one or more health statistics associated with the health of a processing tool based on at least a portion of the trace data and provide the one or more health statistics to a controller. The controller is provided for controlling the processing of the processing tool. The controller is adapted to adjust the processing of a next wafer of the lot based on at least one of the health statistics.